An example of a front fork that supports a front wheel of a straddle-riding vehicle includes one that is interposed between a vehicle body and a front wheel axle in a straddle-riding vehicle, elastically supporting the vehicle body. Such a front fork typically includes a fork main body that is configured to extend/contract, provided with a vehicle body tube connected to the vehicle body of the straddle-riding vehicle and an axle tube fitted with the vehicle body tube and connected to the front wheel axle; and a suspension spring that is housed in the fork main body, configured to bias the fork main body in a direction of extension.
The front fork may be provided with a spring adjuster for axially moving a spring bearing that supports an upper end of the suspension spring so that vehicle heights can be adjusted. An example of a front fork including such a spring adjuster includes one that is provided with a damper cartridge inside a fork main body so as to change damping forces generated by the damper cartridge.
For example, a front fork disclosed in JP 2008-240838A is provided with a bypass passage, inside a damper cartridge, that is configured to bypass a damping force generating passage communicating two working chambers so as to communicate the two working chambers; and a needle valve that is configured to narrow down this bypass passage.
In such a front fork, a valve adjuster for adjusting a valve is provided to a cap that closes an end portion of a vehicle body tube, and an adjustment rod inserted into a piston rod by this valve adjuster and brought into contact with the needle valve is axially moved so as to adjust the damping forces.
On the other hand, a spring adjuster has a tubular shape, coaxially arranged in an outer periphery of the adjustment rod, and screwed in the cap so as not to obstruct the adjustment rod to adjust the damping forces. The spring adjuster is axially movable with respect to the cap when being rotated and is configured to displace a spring bearing that supports an upper end of a suspension spring brought into contact with a leading end and to change indicating positions of the suspension spring so that vehicle heights can be adjusted.